Flower-like zinc oxide nanorod clusters grown on spherical cellulose nanocrystals via simple chemical precipitation method

A facile chemical precipitation approach is presented to fabricate flower-like zinc oxide (ZnO) nanorod clusters by using spherical cellulose nanocrystals (SCNs, with cellulose II crystal structure) as growth substrate. Field-emission scanning electron microscopy results showed that nanohybrids (A-100/11) with flower-like ZnO nanorod clusters could be formed under strongly alkaline (pH 11) conditions using suitable reaction time of 2 h and temperature of 100 °C, while rod-like nanohybrids could be obtained under weakly alkaline (pH 9.3 and 10.5) conditions or low temperature of 90 °C. A possible growth mechanism for flower-like ZnO on SCNs is discussed. Moreover, compared with commercial ZnO and rod-like nanohybrids, the flower-like A-100/11 nanohybrids showed better antibacterial activity against Streptococcus aureus and Escherichia coli, and excellent photocatalytic activity in presence of methylene blue as model dye.